Electrode connector for electric furnace



D. B. RADDATZ 3,530,222

ELECTRODE commcmon FOR ELECTRIC FURNACE Filedbec. 31, 1 968- Sept. 22, 1-970 3 Sheets-Sheet l INVENTOR.

DWIGHT B. RADDATZ BY Mam M, 03

A TTOFP/VEKS Sept. 22, 1970 D. B. RADDATZ ELECTRODE CONNECTOR FOR ELECTRIC FURNACE Filed Dec. 31, 1968 5 Sheets-Sheet 2 III] Q MWN 0Q is? o 9 v QM NM n a mm GA on v\\ N Q g @Q INVENTOR. DWIGHT B. RADDATZ W/(M 0km Sept. 22, 1970 p. B. RADDATZ v ELECTRODE CONNECTOR FOR ELECTRIC FURNACE Filed Dec. 31, 1968 3 Sheets-Sheet 5 INVENTOR. DWIGHT B. RADDATZ BY M4 ATTOl-WVEKSv United States Patent US. Cl. 1316 11 Claims ABSTRACT OF THE DISCLOSURE An electrode connector to connect an electrode to a source of high electrical power, the connector being readily releasable to facilitate rapid repositioning and/or change of an electrode utilized in a furnace such as a glass melting furnace.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to connectors having high electrical power capabilities and more particularly to such a connector for establishing a rapid release connection of an electrode with a high electrical power source.

Description of the prior art It is oftentimes desirable to provide connectors for electrical devices having high power capabilities. Such connectors, for example, are commonly utilized for connecting high power to an electrode, a portion of which extends into the interior of a furnace to heat the contents, such as glass within a glass melting furnace. In such a glass melting furnace, the electrodes, preferably com posed of molybdenum, tungsten, or graphite, are inserted from outside the furnace through suitable apertures in the sidewalls and/or bottom of the furnace so as to extend into the molten glass. The molten glass forms a high resistance path between electrodes to current from an external electrical power source so that the glass in the furnace between electrodes is continuously heated. Heat localization is controlled in accordance with known melting techniques including the relative positioning of the immersed electrodes and electrical phase excitation from the high power source.

As is well known, the electrodes, being submerged in the molten mass, must frequently be replaced due to erosion and the like. Presently, it is not uncommon to provide electrodes adapted to be axially fastened end-toend so as to, in eifect, provide a continuous electrode which is simply further inserted into the furnace as the stub portion within the furnace erodes. In this manner, a change or repositioning of an electrode will not normally require furnace shut-down, although the power to the electrode must be disrupted during change-over or repositioning.

In efforts to minimize power disruptions due to electrode change-overs or repositioning, such electrodes have usually been supported in holders, some of which are capable of allowing electrodes to be easily further inserted into the furnace or repositioned as needed or desired within the furnace. Although many holders of this nature have been suggested and/or utilized, however, a problem still remained because the connectors, through which power is delivered to the electrodes, were not easily removable or even easily loosened from the electrode. Since such connectors must be capable of passing high current, often as high as 3,500 amperes continuously or 5,000 amperes intermittently, this necessarily requires rather massive connectors that must be tightly clamped onto the electrode for proper operation, and particularly to minimize heating loss at the connector and to prevent arcing and other deleterious elfects.

Heretofore, some electrode connectors have been characterized, for example, by a structure having oppositely disposed plates each with a recess facing one another of sufficient size and appropriate shape so that the electrode may be received between the plates, and firmly clamped by a multiplicity of bolts extending between and secured to the plates. While this was satisfactory to establish the connection, it was found that such a connector would be improved by providing a quick release mechanism without adversely aifecting the good connection afforded by this type of connector. A quick release mechanism was also found to be desirable due to such factors as high environmental temperatures and/or the tendency of bolts to stick or otherwise resist loosening.

SUMMARY OF THE INVENTION The present invention provides a connector that solves the problems of the aforenoted prior art. Utilization of the connector of the present invention permits the electrode to be disconnected or moved relative to the connector with a rapidity heretofore unknown.

It is accordingly an object of the present invention to provide an improved connector for transferring high power to an electrical circuit component which connector is easily and readily released from the component.

Another object of the invention is to provide an improved electrical power connector for use with glass furnace immersion electrodes.

A further object of the invention is to provide a connector having oppositely disposed pressure plates adapted to receive the electrode and tightly engage the electrode by application of a force to the plates through camming means.

Another object of this invention is to provide an electrical connector having oppositely disposed pressure plates adapted to receive an electrode therebetween and an integral cam and operator-operative lever arrangement to readily enable the plates to be forced toward one another in closing relation so as to tightly engage the electrode.

A further object of the invention is to provide an improved connector for electrically connecting an electrical power source to heating electrodes, which connector is readily adjustable to receive electrodes of various cross-sectional sizes.

Additional objects of the invention will become apparent from the following description which is given primarily for purposes of illustration and not limitation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the electrode connector of the invention mounted to an electrode and illustrated in a furnace environment;

FIG. 2 is a front plan view of the connector shown in FIG. 1;

FIG. 3 is a side plan view of the connector shown in FIG. 2;

FIG. 4 is a top plan view of the connector shown in FIG. 2;

FIG. 5 is a cross-sectional View of the connector in normal assembled position on an electrode which view is taken along the lines 55 of FIG. 4;

FIG. 6 is a cross-sectional view similar to FIG. 5 but with the connector in released position on the electrode; and

FIG. 7 is a broken-away, cross-sectional view similar to FIG. 5 but with the releasing means of the connector in position for coarse adjustment.

3 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a connector 10 is shown connected to an immersion electrode 12 which extends through a suitable holder 13 positioned in a wall 14 of a glass melting furnace. Holder 13 has a collar 15 for fastening the electrode within the holder as by a locking screw 16. The holder is of conventional type adapted to have a coolant circulated therethrough, which coolant is supplied and exhausted through conduit means 17. Since holders of this type are well known in the art, an electrode holder has been shown and described only generally herein. More specific examples of holders of this type are shown, for example, in U.S. Pats. Nos. 2,693,498 and 3,148,239.

The connector 10 of this invention is attached to a high power source (not shown) by means of braided cables 18, of copper, for instance, and a metallic bus line 20.

Connector 10 includes a pair of spaced arms, or pressure plates, 22 and 24, having oppositely disposed trapezoidal recesses, or notches, 26 and 28, as shown best in FIGS. 2, S, 6, and 7, for receiving electrode 12 therebetween. The plates 22 and 24 have flanges 30 and 32, respectively, extending substantially parallel to each other and to which the power supply lines are connected, which connection, as shown in FIG. 1, is by fastening screws 34 and plates 36, the latter of which has braided cables 18 connected thereto as by welding.

As also shown in FIG. 1, the opposite ends of the braided cables 18 are attached, again as by welding, to plates 40 which are connected, as by fastening screws 42, to the bus lines 20. The plates 40 and 36 may be of aluminum, for example, to provide good current distribution from the bus line 20 to the cables 18 and from the cables to the connector 10.

The braided cables 18 which extend between the bus line 20 and connector 10, can lend mechanical support to the connector so that, upon disattachment of the connector from the electrode, the connector does not have to be otherwise placed or handled. Such an arrangement allows the connector to be maintained in general alignment adjacent the aperture in the furnace which receives the particular electrode holder and electrode.

The plates 22 and 24 of the connector are initially held in spaced relationship with respect to one another at one end of the plates by eyebolt 44 received in open slots 48 and 49 at one side edge of plates 22 and 24, respectively, and by a second eyebolt 46 in similarly shaped slots at the opposite side edge of plates 22 and 24, respectively, one of such slots being shown by numeral 50 in FIG. 3. A pair of clevis brackets 52 and 54 are attached by screws 56 to the plate 22 adjacent slots 50 and 48, respectively. The brackets have holes to receive dowels 60 vertically extending therethrough, which dowels also extend through the eyes of eyebolts 44 and 46, so that the eyebolts may be effectively fixed with respect to the plate 22.

The eyebolts are each threaded at the end opposite the eye so as to each receive a nut 64 against washers 68. A Wear plate 70, having a horizontally extending slot such as slot 72 in each side adjacent the edge slots in plate 24, is provided between the washers and the plate 24 so as to evenly distribute the fastening force of the bolts and nuts upon the plate 24 without damage thereto.

As shown best in FIGS. 2, and through 7, the plates are secured at the opposite side of the electrode 12 from the bolts 44 and 46 by fastening means including a third eyebolt 76 extending through centered edge slots 77 and 78 in the plates 22 and 24, respectively. Eyebolt 76 is pivotably secured at one end by a dowel 79 between oppositely disposed discs 80 and 81, the peripheral surfaces of which provide camming surfaces 82. A handle 83 is connected to the discs so that actuation of the handle turns discs and 81 about dowel 79. The camming surfaces 82 engage a Washer 84, which may be of a type having a spherical or otherwise rounded surface, the washer having a central bore through which the eyebolt 76 extends. A support plate is attached to the plate 22 by means of screws 92 (see FIG. 3) and has an edge slot 93 (see FIG. 4) through which the eyebolt 76 extends. The support plate 90 provides a surface to distribute the force of Washer 84 against the pressure plate 22 and to prevent damage to the pressure plate.

As best shown in FIGS. 5 and 7, the opposite end of the eyebolt 76 is threadedly engaged within an eyerod 96 attached to a clevis bracket 98, the eyerod extending through the edge slot 78 in the plate 24. Eyerod 96 is received between oppositely disposed faces 99 and 100 of the clevis bracket 98 and secured thereto by a dowel 101 extending through bores in the bracket and through the eyerod 96. The clevis bracket 98 is attached by recessed screws 102 to the plate 24.

A rectangular shoulder 104 is welded to the eyebolt 76 and, in the normal assembled position of the connector elements as illustrated in FIG. 5, is vertically extending to a position almost flush with the top of the plate 22.

A stop, or latch, 106 having a slot 108, as best shown in FIG. 4, is secured to plate 22 by screws 110 extending through the slot and into the walls of the plate. The latch 106 is also provided with a notch 112, which is adapted to fit beneath the head of a screw 114 in the plate 22. The latch extends across the central edge slot 77 in plate 22 and above shoulder 104 of the eyebolt 76 so as to vertically constrain the eyebolt relative to the plate 22.

In utilizing the connector of the present invention, the initial maximum spacing between the plates 22 and 24 may be set at one side of the electrode 12 by appropriately adjusting the nuts 64, threadedly engaged upon the respective eyebolts 44 and 46. The initial spacing above the electrode may also be coarsely adjusted with latch 106 drawn to the left from the position shown in FIG. 4 so as to permit the eyebolt 76 in eyerod 96 to be pivoted about dowel 101 and lifted up and out of central edge slot 77 in plate 22 to the position shown in FIG. 7. The handle 83 may be then utilized as a lever to turn eyebolt 76 in the eyerod 96, as shown by arrows 118, to eifect appropriate axial movement therein.

The handle 83 may then be returned to the position shown in FIG. 6 and the latch 106 engaged in normal position above shoulder 104. The connector 10 may be placed on the electrode 12 or the electrode inserted between plates 22 and 24 in recesses 26 and 28, respectively, upon handle 83 being positioned as shown in FIG. 6. The camming surfaces 82 toward the flat portion of the clevis are less distant from the pivot position about dowel 79 than the distance at any other portion so that the electrode 12 is free to move in spaces created between the loose plates and electrode upon the handle 83 being so positioned. Another section of an electrode (not shown), upon loosening of screw 16 (see FIG. 1), may be attached to the end 122 of electrode 12 so that the latter may be further shoved through holder 13 into the furnace. The handle 83 of connector 10 may then be pivoted back to the position shown in FIG. 5 wherein the camming surfaces 82 of the clevis faces 80', 81 bear upon washer 84 causing the plates 22 and 24 to be forced toward one another in a closing relation as limited only by the electrode therebetween which is thereby tightly clamped in recesses 26 and 28.

It has been found that the trapezoidal configuration of the recesses is more satisfactory than a configuration in which the recesses are form fitted to the shape of the electrode. In a constructed embodiment of the invention, a clamping force of over 1800 pounds has been applied to a molybdenum electrode utilized in a glass furnace melting process. The connector was utilized to pass over 3700 amperes at 250 volts to electrodes from a high power electrical source over extended periods of time without any failure.

Although only one embodiment of the invention has been shown and described, various modifications as may appear to those skilled in the art are intended to be within the contemplation of the invention as defined in scope by the claims.

What is claimed is:

1. An electrode connector comprising: a pair of spaced electrically conductive plates adapted to receive an elec trode therebetween, each of said conductive plates including means at one side portion of the electrode adapted to be connected to power supply means; first adjustable connecting means including a plurality of bolts for adjustably fastening said plates in a predetermined spaced relationship at one side of the electrode; and second adjustable connecting means including camming means for releasably fastening said plates at the other side of said electrode so that said plates are relatively movable to tightly engage and substantially disengage an electrode therebetween upon actuation of said camming means in closing and opening directions, respectively.

2. The electrode connector as defined in claim 1 wherein said second connecting means includes fastening means one portion of which is an eyebolt connected with one of said plates, and a second portion including pivot means connected to said camming means so that said camming means pivots about an axis substantially parallel to the axis of an electrode between said plates with actuation of said camming means in one predetermined manner effecting relative movement of said plates to clamp an electrode therebetween and actuation of said camming means in a second predetermined manner causing release of an electrode between said plates.

3. The electrode connector as defined in claim 2 wherein the first portion of said fastening means also includes an eyerod for connecting the one of said plates to said eyebolt whereby the initial spacing between said plates prior to actuation of said camming means may be coarsely adjusted by effecting axial movement of said eyebolt in said clevis means.

4. An electrode connector comprising: first and second electrically conductive plates spaced one from the other with said plates having mating notches in one face for receiving and clamping an electrode therebetween, each of said plates having aligned openings therein near a first edge with said edge being adapted to be connected with power supply means; first elongated fastening means extending through said openings near said first edge of each said plate for substantially securing said first edges of said plates in a predetermined spaced relationship; second elongated fastening means including first and second portions having adjustment means at the first end of each portion to effect relative lengthwise adjustment of said second fastening means, the second end of said first portion being connected to a second edge of one of said plates and the second end of said second portion having pivot means; a lever having a cam surface at one end and a handle at the other end, said lever being pivotably mounted to said pivot means; and shoulder means between the other face of the other of said plates at a second edge thereof and said cam means whereby actuation of said handle in one direction causes said cam surface to engage said shoulder means to effect closing movement between said second edges of said plates to thereby tightly clamp an electrode in said notches, and actuation of said handle in the other direction allowing opening movement between said second edges of said plates to thereby release an electrode clamped between said notches.

5. The electrode connector as defined in claim 4 wherein the second end of said first portion of said second fastening means is pivotably connected to the second edge of said first plate; and wherein said second edge of the other of said plates has an upwardly opening slot for receiving said second portion of said second fastening means so as to permit said second fastening means to be pivoted away from the other of said plates to effect adjustment of said second fastening means; and further including stop means connected to the other of said plates and adapted to extend across the upwardly extending slot whereby pivotal movement of said second fastening means out of the slot may be prevented while said stop means extends across the slot.

6. The electrode connector as defined in claim 4 wherein said plates are capable of conducting high current exceeding 3,000 amperes for long time periods.

7. An electrode connector comprising: electrically conductive means adapted to be connected with a source of electrical power, said electrically conductive means including first and second relatively movable plates having facing portions for receiving and positioning an electrode therebetween; and plate positioning means including camming means actuatable to effect relative movement within a predetermined distance range between said plates toward one another to a closed position and away from one another to an open position, said plate positioning means also including range adjustment means connected between said camming means and one of said plates for controlling initial spacing of said plates relative to one another when said camming means is in engagement with the other of said plates so that movement of an electrode received'between said plates is permitted relative to said plates when said camming means has been actuated to said open position and precluded when said camming means has been actuated to said closed position whereby electrodes of varying dimensions may be quickly secured in and released from said connector.

8. The electrode connector of claim 7 wherein said camming means includes a rod having a lever actuated cam pivoted on one end thereof, and wherein said range adjustment means includes an internally threaded eyerod receiving the end of said rod opposite said cam, said rod being externally threaded at the end opposite said cam.

9. The electrode connector of claim 8 wherein said cam includes one portion having a substantially flat recessed surface and wherein said eyerod is pivoted on one of said plates so that said rod can be easily pivoted from the normal use position adjacent to the other of said plates.

10. The electrode connector of claim 9 further characterized by lock means attached to the other of said plates to prevent undesired pivoting of said rod.

11. The electrode connector of claim 7 further characterized by second plate positioning means for adjustable spacing of said plates at the edge of said plates opposite to said first plate positioning means.

References flited UNITED STATES PATENTS 573,041 12/1896 Schindler 13-16 1,472,215 10/1923 Goughnour 339255 1,278,171 9/1918 La Chance 1316 X 2,337,333 12/1943 Le Tourneau l316 X HIRAM B. GILSON, Primary Examiner US. Cl. X.R. 13-14; 339-255 

